docs: def enableSync(self, url, definition = None):
          """Enables Sync capability for an AGOL feature service.
  
          Args:
              url (str): The URL of the feature service.
              definition (dict): A dictionary containing valid definition values. Defaults to ``None``.
          Returns:
              dict: The result from :py:func:`arcrest.hostedservice.service.AdminFeatureService.updateDefinition`.
  
          """
          adminFS = AdminFeatureService(url=url, securityHandler=self._securityHandler)
  
          cap = str(adminFS.capabilities)
          existingDef = {}
          enableResults = 'skipped'
          if 'Sync' in cap:
              return "Sync is already enabled"
          else:
              capItems = cap.split(',')
              capItems.append('Sync')
              existingDef['capabilities'] = ','.join(capItems)
              enableResults = adminFS.updateDefinition(json_dict=existingDef)
  
              if 'error' in enableResults:
                  return enableResults['error']
          adminFS = None
          del adminFS
          return enableResults